微通道内气液两相流空隙率与压力降对微反应器的热质传递性能有显著影响,是微反应器的重要设计参数。采用高速摄像仪和压力测量系统分别对矩形微通道内单乙醇胺水溶液化学吸收CO2过程的空隙率和压力降进行了研究,考察了弹状流下气液两相流量与化学反应速率对空隙率及压力降的影响。结果表明:当液相流量一定时,微通道内空隙率和压力降均随着气相流量的增大而增大,空隙率随化学反应速率的增大而减小,压力降随化学反应速率的增大而增大;当气相流量一定时,随着液相流量和化学反应速率的上升,微通道内空隙率下降,而压力降上升。提出了微通道内伴有化学吸收的空隙率和压力降的半理论预测模型,模型平均误差分别为15.79%和11.12%,显示了良好的预测性能。
Void fraction and pressure drop of gas-liquid two-phase flow in microchannel have remarkable influence on performance of mass and heat transfer,and also are important design parameters of microreactor.A high speed camera and a pressure measuring system were used to investigate void fraction and pressure drop of CO2 chemical absorption by monoethanolamine(MEA)aqueous solution.The effects of gas/liquid flow rate and chemical reaction rate were studied under Taylor flow.Experimental results showed that,for a given liquid phase flow rate,both void fraction and pressure drop increased with increasing gas phase flow rate,and void fraction decreased while the pressure drop increased with increasing chemical reaction rate.For a given gas flow rate,void fraction decreased while pressure drop increased with increasing liquid phase flow rate and chemical reaction rate.Two semi-theoretical models were proposed for predicting void fraction and pressure drop of gas-liquid two-phase flow accompanied with chemical absorption in microchannel,respectively.The average deviations of the models were 15.79% and 11.12% respectively for void fraction and pressure drop,showing good prediction.